A post hoc analysis of the ARCADIA long-term extension (LTE) programme revealed that the majority of patients who had already responded to nemolizumab maintained both itch relief and skin improvements through 104 weeks of continued therapy [1]. These findings highlight the durability of interleukin-31 (IL-31) receptor blockade as a long-term maintenance strategy in moderate-to-severe atopic dermatitis (AD).

Nemolizumab targets the IL-31 receptor, interrupting a neuroimmune signalling pathway implicated in pruritus, skin barrier dysfunction, and inflammation. Previously, the pivotal  ARCADIA 1 (NCT03985943) and ARCADIA 2 (NCT03989349) trials demonstrated rapid and clinically meaningful improvements in both itch and skin manifestations of AD [2]. The current analysis evaluated the long-term durability of these responses.

The ARCADIA LTE (NCT03989206) was a prospective, multicentre, open-label extension programme that enrolled patients aged ≥12 years with moderate-to-severe AD from 7 phase 2/3 studies, as well as newly recruited adolescents. Participants received nemolizumab 30 mg every 4 weeks alongside low- or medium-potency topical corticosteroids, with or without topical calcineurin inhibitors. At the July 2024 data cut-off, 1,901 of 1,903 enrolled patients had received treatment, and 1,062 (55.9%) had completed 104 weeks of follow-up. Responders at LTE baseline were categorised according to the following criteria: a ≥4-point improvement in SCORing Atopic Dermatitis (SCORAD) VAS-itch score (n=618), a near itch-free state defined as SCORAD VAS-itch <2 (n=383), clear or almost clear skin according to the Investigator´s Global Assessment (IGA 0/1 (n=315)), Eczema Area and severity Index (EASI-75; n=441), and EASI-90 (n=291). The proportion of patients maintaining each response through week 104 was assessed using an observed-cases analysis.

Responses were highly durable over the 2-year treatment period. At week 104, 95.2% of patients maintained a ≥4-point itch improvement in itch score, while 89.6% remained itch-free or nearly itch-free. Skin responses were similarly sustained, with 96.6% and 92.3% of patients maintaining EASI-75 and EASI-90 responses, respectively, and 86.5% retaining an IGA score of 0/1. The long-term safety profile was consistent with that observed in the pivotal phase 3 studies. Treatment was well tolerated; the most frequently reported treatment-emergent adverse events were infections and respiratory disorders, and no deaths were reported.

Overall, these data support nemolizumab as an effective long-term maintenance treatment for patients with moderate-to-severe AD, providing sustained improvements in both itch and skin disease over 104 weeks.

1. Thaçi D, et al. Long-term (up to 104 weeks) maintenance of itch and skin responses with nemolizumab treatment in patients with moderate-to-severe atopic dermatitis – post hoc analyses from the ARCADIA long-term extension trial. Abstract 76623, American Academy of Dermatology Annual Meeting 2026, 27–31 March 2026, Denver, Colorado, USA.
2. Silverberg JI, et al. Lancet 2024;404 (10451):445-60.

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Rademikibart produced rapid and clinically meaningful improvements in skin clearance and pruritus in adults and adolescents with moderate-to-severe atopic dermatitis (AD). Moreover, response rates continued to deepen over the course of 1 year of treatment.

Despite the expanding biologic armamentarium for moderate-to-severe AD, there remains clinical interest in agents that combine high efficacy with a tolerability profile that minimises class-typical concerns such as conjunctivitis. The phase 3 RADIANT-AD trial (NCT06477835) was designed to evaluate whether rademikibart, administered every 2 weeks, could meet these expectations in adolescents and adults whose disease was inadequately managed with topical therapy alone [1].

As Prof. Cheng Zhou (Peking University People’s Hospital, China) explained, the randomised, placebo-controlled trial included 2 co-primary endpoints assessed at week 16: the proportion of participants achieving an Investigator’s Global Assessment (IGA) score of 0 or 1 (clear or almost clear skin) with a ≥2-point reduction from baseline, and the proportion achieving at least a 75% improvement in the Eczema Area and Severity Index (EASI) 75. At week 16, IGA 0/1 was achieved by 47.4% of patients receiving rademikibart versus 17.6% with placebo, and EASI 75 by 74.2% versus 34.4%, respectively (both P<0.001). Responses continued to deepen over time, reaching 87.1% (IGA 0/1) and 96.6% (EASI 75) at week 52. Both endpoints demonstrated robust separation from placebo.

Pruritus outcomes were similarly favourable. A clinically meaningful improvement of ≥3 points in pruritus score was achieved by 54.7% of rademikibart-treated patients compared with 27.5% receiving placebo at week 16 (P<0.0001), increasing to 91.2% by week 52. Analyses using the more stringent ≥4-point reduction threshold, considered clinically meaningful, showed a consistent and durable treatment effect. Additional patient-reported outcomes and quality-of-life data are expected to be reported at a later stage.

The safety profile through week 16 was comparable to placebo and remained consistent with sustained IL-4/IL-13 inhibition through 1 year. Serious adverse events, treatment discontinuations, and injection-site reactions were infrequent, and no new safety signals emerged over the 52-week period. Notably, conjunctivitis occurred in 3.9% of rademikibart-treated patients versus 3.1% in the placebo group. Most adverse events were mild to moderate in severity.

1. Zhou C, et al. Rademikibart monotherapy in adult and adolescent patients with moderate-to-severe atopic dermatitis (AD): A 1-year, phase III, randomized, double-blinded, placebo-controlled trial (RADIANT-AD). S023: Late-Breaking Research: Session 1. AAD 2026, 27–31 March, Denver, CO, USA.

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